TOPCon Solar Cell Sidewall Texturing for Leakage Suppression

The patent applies different surface treatments to different locations: the front and back surfaces receive doping processes for conductivity, while the lateral surfaces receive etching treatment to remove doping elements and prevent leakage. This localized differentiation resolves the contradiction by allowing conductivity improvement where needed while preventing harmful leakage where it occurs.

The patent segments the surface treatment process into distinct steps: first applying doping to front and back surfaces, then selectively etching the lateral surfaces to remove doping elements. This segmentation allows the beneficial doping effect on main surfaces while eliminating the harmful leakage effect on lateral surfaces.

The patent performs the etching treatment on lateral surfaces as a preliminary step before applying the passivated contact layer. This preliminary action ensures that doping elements are removed from lateral surfaces beforehand, preventing leakage channels from forming during subsequent processing, while integrating smoothly into the existing manufacturing flow.

The patent controls the etching process parameters (etching solution concentration, temperature, time) to achieve selective removal of doping elements from lateral surfaces without excessive etching that would damage the structure. This precise parameter control enables the leakage prevention function while keeping the process manageable and integrated into standard manufacturing.